This invention relates to a buzzer, particularly to one possible to give out high and medium range of sounds in an overwhelming and far-reaching manner.
A conventional buzzer shown in FIG. 1, is what is called a coil moving buzzer, including a base 10, a T-shaped core 11 fixed inside the base 10, a magnet 12 surrounding the core 11, and a washer 13 on the magnet 12, a sound film 14 above the core 11, and an equalizing sound mechanism 15 on the sound film 14. Further, a coil 16 is fitted in a gap between the sound film 14 and the T-shaped core 11 together with the washer 13. Then the coil 16 may be attracted to or repelled off by the permanent magnet formed by the T-shaped core and the washer 13 when the coil 16 is electrified and magnetic force is produced. Therefore, the sound film 14 may vibrate by the magnetic force to produce sound, which is then spread out around with the sounding mechanism 15. However, this conventional coil moving buzzer depends on the sound film 14 vibrated by the magnet 12 and the T-shaped core 11, which has to have a large size to cause heavy weight, not easy to carry. Thus conventional vibrating buzzers have been devised to be rather light.
A first conventional vibrating buzzer 2 shown in FIG. 2, includes a base 20, a vibrating plate 21 consisting of a copper plate 210 and a ceramic plate 211, and a sounding mechanism 22 fixed above the vibrating plate 21. When the vibrating plate 21 is electrified, it vibrates up and down to give out sound, which is then transmitted and dispersed out and around. The vibrating plate 21 is then and very light, made of copper and and ceramic, improved in the weight much lighter than the conventional coil moving buzzer mentioned above. Nevertheless, sound given out by the vibrating plate is not intensified auxiliary by a sound film, but directly transmitted and dispersed with the sounding mechanism 22. So sound volume, dB (decibel), and sound range are still small, substantially including high shrill sound only, devoid of medium sound range, with weak sound transmitting force impossible to reach far.
Another conventional vibrating buzzer shown in FIG. 3, includes a vibrating plate 30, a funnel-shaped sound film 31 additionally fixed on the outer edge of the vibrating plate 30, which has its outer edge connected to the mouth edge of the base 32 for intensifying sound produced by the vibrating plate 30. However, the sound film 31 is connected to the outer edge of the vibrating plate 30 with a "line" only, resulting in poor mutual vibration together. In other words, the sound film 31 is in no position to intensify much the sound produced by the vibrating plate 30. Therefore, the sound given out by this conventional buzzer is still weak, shrill and a small range.